1. Field of the Invention
The present invention relates to a horizontal tact switch in which a plurality of separate contacts may be electrically connected together via a manual depression on the tact switch.
2. The Prior Art
Tact switches which have quick response to a manual depression have been used in many appliances such as in telephone sets, microwaves, remote controls, TV sets, and etc. Most of the tact switches are made of vertical type rather than horizontal type, therefore they do not meet the low profile requirement for some appliances. One horizontal tact switch has been disclosed in U.S. Pat. No. 5,660,272 which includes a snap metal dome lying over an inner contact and an outer contact, and an actuator arrangement for actuating the snap metal dome upon receiving a manual depression from a horizontal direction. The actuating arrangement includes a sheet metal force transfer member with a horizontal plate and with a deflectable lever, and an actuator device or pusher with a ramp that can engage the lever to deflect it. Normally, the snap metal dome engages them. The outer contact via a peripheral portion thereof is separated from the inner contact. Upon depression on the pusher, a horizontal forward movement of the pusher deflects the front of the lever downwardly, to depress the middle portion of the snap metal dome to engage the inner contact, thereby electrically connecting the outer contact and the inner contact. When the depression is released, the metal dome recovers to the original shape, the lever moves upwardly, and the pusher moves horizontal backward to the original position. A user will feel a click when he/she depresses and releases the pusher. Although this tact switch works well for switching connection between two contacts, it is not easy to simultaneously connecting four contacts by modifying this tact switch. Moreover, the sheet metal force transfer member is apt to have unwanted movement upon receiving force from the pusher. This is because the sheet metal force transfer member only rests on an upper surface of a lower housing part. When the lever of the sheet metal force transfer member receives strong push force from the pusher, the horizontal plate may deflect or move due to insufficient retention to the lower housing part. It is requisite to provide an improved structure of a tact switch for solving the above problems.